TripIt
This free organizer app keeps all your travel documents in one place. You simply forward your flight, hotel, and rental car confirmation emails to TripIt, then watch it automatically organize everything into a master itinerary which you can access anywhere anytime.Find in iTunes
Currency Exchange
This money converter is a must-have when you're on the go and it's free to download. Use it to get up-to-date currency exchange rates. Plus it comes with a convenient calculator to convert any amount from one currency to another -- very useful when shopping!Find in iTunes
Hipmunk
Hipmunk takes the agony out of flight and hotel search. This clever app lists available flights ranked by costs as well as "agony" factor (i.e. how many stops you'll have to make and the flight duration). Hotel results are shown on a map so you can see exactly where you'll be staying.Find in iTunes
Foodspotting
Perfect for globetrotting foodies, this app is your guide to the popular and highly raved restaurants and eateries in your destination city, as rated by user reviews and pictures. You can search for nearby restaurants using your current GPS location or browse selections by category or rank.Find in iTunes
HearPlanet
This is a comprehensive talking guidebook that lets you search by destination or tourist attraction and plays aurally on your device telling you what to see and where to go. The Lite version is free.Find in iTunes
Google Translate
Google Translate allows you to translate words and phrases between more than 60 languages. For most languages, you can even speak your phrases into the phone and hear the corresponding translations. Free to download.Find in iTunes
Skype
Save on international calling -- install Skype app and you can make use of the WiFi to make free (or cheap) calls. App is free to download.Find in iTunes